1. Field of the Invention
The present invention relates to a keypad structure and a method of manufacturing the same, and more particularly, to a thin-type keypad structure having planar metal figures with three-dimensional floating effect.
2. Description of the Prior Art
Electronic products such as cell phones, personal digital assistants (PDAs) usually have keypad keyboards. In the present market, keypad keyboards are mainly categorized into metal keypad keyboards with metallic luster and common plastic keypad keyboards. Conventionally, the metallic luster and the figures such as numerals, symbols and English letters formed on the keypad keyboards are manufactured by virtue of print production or laser carving method, whereas only two-dimensional flat visual effect may be achieved. Also, the aforementioned figures may be stripped off with ease and damaged due to frequent pressings. For this reason, in order to enhance the protection for the figures and increase three-dimensional beauty as well, the technology for forming figures on the bottom surface of the keycap component has developed.
For example, Taiwan patent number M353416 discloses a keypad keyboard having metal figures. As illustrated in FIG. 1, the metal figures are covered by the outer transparent layer. The keypad keyboard includes a substrate 1 and a plurality of keycaps 2. The substrate 1 has a first surface 11 and a second surface 12 on the opposite sides, and the substrate 1 may be soft material such as rubber, but not limited thereto. Pluralities of plungers 13 are disposed on the second surface 12 of the substrate 1. Also, the keycap components 2 are respectively disposed on the top of the substrate 1. In this embodiment, the keycap components 2 are disposed on the top of the first surface 11 of the substrate 1. Each of the keycap components 2 has at least a metal FIG. 21 and an outer transparent layer 22, and the metal FIG. 21 with micro-shaped protrusions are disposed on the surface corresponding to the transparent layer 3 and disposed on the top of the first surface 11 of the substrate 1. The outer transparent layer 22 covers metal FIG. 21, such that the metal FIG. 21 are embedded inside the outer transparent layer 22. The metal FIG. 21 include numerals, symbols and English letters or the combination of the aforementioned metal figures, but are not limited thereto. In addition, the thickness t of the metal FIG. 21 is between 0.04 and 0.07 mm, and is preferably between 0.05 and 0.06 mm for optimized effect. Also, the outer transparent layer 22 is formed by UV-cured resin, and the plungers 13 of the substrate 1 correspond to the bottom of the keycap components 2.
The keypad keyboards of the electronic products have to be relatively thin and small for the devices with reduced size and weight as desired so as to accord with the demand of the market. Consequently, there is still a need for a novel keypad with a thin and small structure.